The proposed projects include: 1) continuation of studies in the rat, and particularly in the monkey, on the relationships among vascular morphology, connective tissue content and lysosomal activity and manipulations of the hormonal, hemodynamic or dietary status of the animal, 2) use of tissue culture and cell fractionation techniques to isolate the influence of pharmacological or hormonal factors on control of the proliferative and synthetic responses of aortic smooth muscle cells, including studies of connective tissue synthesis, formation and activity of lysosomes, and cellular uptake of materials from medium and 3) studies of the role of the carotid sinus in blood pressure control by experimental manipulation of its wall properties.